Carpenter&#39;s square.



Patented Oct. 19,1909.

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L. E. BAILEY. GARPENTEBS SQUARE. APPLICATION FILED TUNE 9, 1908l937,202.

VIIIII QOMMON RAFTERS YOUR TOP CUTI vY0UR' RAFTER HALF THE WIDT 0F .SPANIS'YOUR TOP GUT.

UF rrr UNITED sTATEs PATENT oEEioE.

LOUIS EUGENE BAILEY, OF HASKELL, TEXAS.

cAErENTEEs SQUARE.

Speccation of Letters Patent.

. Patented Oct. 19, 1909.

Application led. June 9, 1908. Serial No. 437,604.

This invention relates to a tool for the use of carpenters and joinersand known as a framing square, a carpenters square, a steel square etc.;and has for its main object to provide a square of the type mentionedwith a newly devised table to be stamped on one face or side of theblade of the square by means of which table the square may be applied torafters and other timbers and boards, and the angles and lengthsrequired on which they are to be cut quickly and easily ascertained. Onthe same face of the tongue of the square are two'scales which are usedwhen the spans or widths of buildings are given in feet and fractionsthereof, these scales to be used for measuring only the fractions offeet, or in other words, inches. The opposite face of the squarecontains the usual board measure scale on the blade, and directions onthe tongue for using the table of rafter cuts.

The invention will be more clearly understood from the followingdetailed description and the accompanying drawing forming a part of thisspecification, in which;

Figure 1 is a view of one face of the square with a portion removed fromthe blade and from the tongue, and Fig. 2 a similar view of the oppositeface.

Like reference characters are used forthe same parts in both gures.

The square l is made as usual of sheet steel with a blade 2, twenty-fourinches long and two inches wide, and a tongue 3, eight' een inches longand one and five eighths inches wide the blade and tongue forming a'Vtrue right angle. The inner and outer edges of the square on both facesare provided with the usual graduations 4 into inches and fractionsthereof, but if desired metrical graduations may be substituted for theinch graduations more commonly employed. On` one face of the blade 2 ofthe square is placed a table 5, to be described later, situated betweenthe two edge graduations and eXtendving from end to end of the blade.The opposite face of the blade has thereon the usual board measure 6, sowell known to those skilled in the art that description thereof isldeemed unnecessary. That face of the tongue 3 continuous with the faceof the blade 2 bearing the table 5, carries two scales 7 and 8 betweenthe edge graduations 4. These two scales 7 and 8 extend from a line a,running across the tongue continuous with the inner edge of the blade 2.A brief explanation 10 on the use of the table 5 is impressed in theopposite face of the tongue between the edge graduations 4.

Referring now to the table 5, it will be seen to comprise ten parallellongitudinal lines b extending from the eXtreme end of the blade 2 to atransverse line c near the outer graduation 4 on tongue. Between theselines b are included nine spaces d each space containing figuresimmediately under the inch divisions of the outer graduation 4, whichfigures when viewed collectively l will `be seen to form a column ofligures In each under each of said inch divisions. space cl, preferablyat the end of the table 5 near the outer edge of the tongue 3, is placeda word or abbreviation indicative of the use to which the gures in thesame longitudinal space are to be put. with the outermost space thewordsand abbreviations which follow in order are Degree, the angle ofthe rafters in circular measure: Pitch, the common name for Beginningthe angle or inclination of rafters: T. C. C.

vnumber of inches to be measured off on the outer graduations 4 of theblade and tongue respectively to obtain the correct angles for cuttingthe top and bottom ends of common `rafters:"S. B. C. R. (side bevelcommon rafter) indicates the inches to be set olf on 'the edges of thesquare to get the bevel or side angle of a rafter where it meets a hipor valley rafter: T. C. H. & V. (top cut hip and valley) and B. C. H. &V (bottom cut hi and valley) give the inches to be counted og on theedges of the square to obtain the correct top and bottom cuts for hipand valley rafters: S. B. H. & V. (side bevel hip and valley) gives thecorrect measurements to be used when a hip or valley rafter requires aside bevel to fit against the side of the ridge plate or a commonrafter, and Back bevel are the measurements for the ends of hip andvalley rafters and ridge plates when they are beveled from both sidestoward the center line of the rafter or plate to form either an exterioror an intefraction below each inch mark on the outer edge of the square.These fractions, beginning with l/24C under the l inch division line andending with 1.0. (Q4/24) at the end of the blade, each indicates theratio which the perpendicular side of a right triangle having a heightequal to the number of inches in the graduation immediately above thefraction, bears to the base of said triangle having" a constant lengthof twenty-four inches, or in other words the ratio of the height of aroof to Athe span or width of a building to be covered thereby, and whenthe fractions are reduced to twenty-fourths of an inch, the numeratorsrepresent the rise in inches of a roof for each twelve inches or runningfoot of the span of the building. For instance, l/l pitch equals 6/24pitch, the angle of the roof therefore will be a rise of six inches toeach foot measured in a horizontal plane. The next space below Pitchheaded T. C. C. R. and all the others have two numbers below each pitchnumber. The numbers in the space T. C. C. R. indicate the lengths to bemeasured on the outer edges of the blade and tongue of the square. Thus,if the pitch is l/t it will be seen that the numbers in the T. C. C. R.space below l/t pitch are 6-12, the square therefore must be measuredfrom the angle six-inches on the tongue and twelve inches on the bladeand these division lines placed exactly at one edge of the rafter lyingflat, or on a straight line thereon running from end to end. A linedrawn at an angle across the rafter guided by the outside of the bladewill give the exact direction of cut for the top of the rafter. Runningthe eye from one end to the other of the space (T. C. C. R.) it will beobserved that the first of each two numerals is the same as that of theinch mark just above it, and that the second numeral in each case istwelve. The pitch triangle is, therefore, for each pitch, twelve inchesfor base, the first of the two numbers give the rise per foot ru'n andthe hypotenuse or line connecting these two numbers in the scales on thesquare the angle or -pitch of the roof.

The common rafters as is well known rise from each side of the wall andmeet in the center of the building at the ridge. Therefore, incalculating the length of a rafter, one-half the span or width of thebuilding is used. For example, a building twenty feet wide one-halfthereof is of course ten feet and this multiplied by the height per footwhich in a one-fourth pitch is six inches, gives the height of the roofat the top of the ridge-pole above the plane of the wall plates sixtyinches or five feet. Now, having drawn the line for the top cut on arafter for Looka building twenty feet wide if the square be moved alongthe rafter a distance equal to ten times the length of the line of thehypotenuse extending between the twelve and the six inches marks on thesquare and a line be drawn across the rafter against the tongue, theresult will give the correct length of the rafter and the angle for thebottom cut thereof. The numbers in the saace S. B. C. R. give thenumbers for marking the side bevel of cripple or jack rafters or thosethat, extend from the wall plate to the hip rafter and from the ridgeplate to the valley rafter. As these rafters are parallel to the commonrafters the same base, twelve inches is used, but the other number givenis the length of the hypotenuse of the pitch triangle. The square isapplied to the top of the rafter in this case and the inches indicatedmeasured oif on the square as heretofore described, then placed on topof the rafter and the mark always drawn on the side of the square onwhich the larger of the two numbers was measured and never on the sidemeasuring twelve inches. The lengths of these rafters are obtained by arule well known to carpenters and framers. To get the top and bottomcuts of hip and valley rafters, the number seventeen is used as the baseof the pitch triangle for reasons well known to those skilled in the artand the operation is the same as for similar cuts on common rafters.Side bevel hip and valley rafters (S. B. H. & V.) are bevel cuts on thesides of the upper ends of these rafters where they meet the side of aridge plate or common rafter and the numbers indicated are used forobtaining this angle in the same manner as described for getting theside bevel of cripple or jack rafters. Back bevel numbers are used forback beveling the `ends of hip and valley rafters, that is to say,cutting the hip rafters to a point to form an exterior angle at the endand making an angular notch in the valley rafters, thereby producing aninterior angle at the ends of these rafters. To find the lengths of backbeveled hip rafters, they should be cut first and then begin themeasurement where the angle meets the side of the rafter, but in thecase of valley rafters, the measurement begins at the end so it isimmaterial whether the length of the rafter is made before or after thecut.

lVhen the width or span of a building is given in feet and inches,various means have been devised for calculating the additional length tobe given the rafters to include the inches of the span. To avoid thenecessity of calculating these fractional divisions of a foot, correctlycalculated scales 7 and 8 respectively for common rafters and for hipand valley rafters will be found on the face of the tongue 3 on the sameside of the square as the table 5. The scales 7 and 8 consist oflongitudinally extended parallel lines and cross lines between each twoparallel lines arranged to form between said parallel lines spacesdiffering in length, said spaces having values according to a commonfractional part of a foot run and varying pitches. Each of these varyingspaces is provided with an index mark to denote the pitch which givesthat particular length of space. To use these scales let it be assumedthat the span of a building` is eighteen feet siX inches with a pitch of1/4. The half span is first measured on the rafter as usual. Then, withthe dividers, measure the length of the space in the common rafter scale7 containing the fraction 1/4. Turning now to the rafter which has beenmeasured for the half span or nine feet, add to the length thereof threesteps of the dividers or onehalf the number of inches in the span. Bythis simple means'the correct length of a rafter can be quickly obtainedwhatever the length of the span in feet and fractions thereof. The scale8 is used in a similar manner for hip and valley rafters.

outer' edges ofthe scales for making all ani gular cuts in theconstruction of roofs; and when the span or width of buildings is givenin feet and inches, the scales 7 and k8 on the tongue give theadditional length to be added to the common rafters and hip and valleyrafters to compensate for the inches in the span.

By means of this scale, all the timbers necessary for a roof may bemeasured, marked and cut out with great eXactness before beginning theconstruction of the roof.

lVhat is claimed is l. A square containing a table calculated for wholenumbers, and another table calculated for fractions, the last-mentionedtable consisting of a series of parallel lines, and cross-linestherebetween arranged to form between said parallel lines spaces ofdifferent lengths, each of said spaces having a value corresponding tothe fractional part of a foot, and index marks on said spaces denotingthe value thereof.

2. A square having a blade containing a table calculated for wholenumbers, and a table on the tongue of the square calculated forfractions, the last mentioned table consisting of a series oflongitudinally extending parallel lines, and cross-lines therebetweenarranged to form between said parallel lines spaces of differentlengths, each of said spaces having a value corresponding to thefractional part of a' foot, and index marks on said spaces denoting thevalue thereof.

In testimony that I claim the foregoing as my own, I have hereto affixedmy signature in the presence of two witnesses.

LOUIS EUGENE BAILEY.

Witnesses:

A. E. MYLES, E. S. VVHITELAW.

